Material such as film, fiber, woven and nonwoven fabric with adsorbancy

ABSTRACT

Compositions that can be used to adsorb low concentration, of unwanted or target substances from a dynamic fluid stream or from an enclosed static vapor phase. Such adsorbency can be obtained with thermoplastic materials used in the form of bulk polymer or a film, fiber, web, woven fabric, non-woven fabric, sheet, packaging and other such structures including or surrounding the enclosed volume. The concentration should be reduced to non-offensive sensed limits or a limit that does not produce a biological response.

This application is being filed as a PCT International Patentapplication on Jul. 27, 2011, in the name of CELLRESIN TECHNOLOGIES,LLC, a U.S. national corporation, applicant for the designation of allcountries except the U.S., and Willard E. Wood, a U.S. Citizen,applicant for the designation of the U.S. only, and claims priority toCanadian Patent Application Serial Number ______, filed Jun. 23, 2011;the contents of which are herein incorporated by reference.

Compositions can be used in an article or structure, including fiber,film and fabric that can adsorb or remove low concentration of anunwanted or target substance from gas or vapor under static and dynamicconditions. A fundamental problem exists in adsorbing low concentrationsof a variety of unwanted or target substances from a gaseous volume orvapor phase in a static or a dynamic condition. A static condition ischaracterized by minimal or no flow of gas or vapor. Dynamic conditionis characterized by a flow of at least 1 liters·min⁻¹ (16.6 cm³·sec⁻¹)through a layer or aperture. At minimal parts per millionconcentrations, adsorbing significant quantities of a variety ofunwanted or target substances become a significant problem. Adsorptionoccurs when a solid surface is exposed to and accepts or bonds to one ormore unwanted or target substance (undesired molecules) in a fluid (gasor liquid droplets) in an area of the interface between the fluid andthe solid. Low partial pressure of an unwanted or target substancereduces the tendency to absorb. The term adsorption deals with theprocess in which the unwanted or target substance (undesired molecules)accumulate in an interfacial layer between a fluid and a surface. Theadsorption (a surface process) process is accompanied by absorption,i.e. the penetration of the gas or liquid into the solid phase. Thetotal uptake and removal (adsorption and absorption) of gas or liquid bya solid material is sorption.

At low concentrations in the enclosed volume or enclosed ambient vaporphase, there is very little physical cause, on an energetic basis, forthe undesired molecules to be adsorbed.

Adsorption theory is based mainly on the Langmuir (concept of monolayeradsorption, formed on energetically homogeneous solid surfaces) and BET(multilayer isotherm equation proposed by Brunauer, Emmett and Teller)equations, capillary condensation theory, Polanyi potential theory(adsorption potential and the characteristic adsorption curve, which areindependent on the of adsorption temperature) and the DR equation(adsorption based on considerations of adsorption energies) related tothe latter. The Langmuir and BET equations have distinct deviations fromexperimental values particularly in the range of low and high relativepressures.

A problem arises in the divergence between theory and experimental. Thissuggests the existence of additional physical factor that influencesadsorption processes; an effect resulting from interactions in theinterface area. The disparity is related to the energetic heterogeneityof most real solid (polycrystalline and amorphous) adsorbent. Withoutwishing to be bound by any theory, it is believed that it has beenexperimentally shown that the concept of surface heterogeneity (besidesdefects on the solid surface) can be disturbances in the structure. Thepresence of structural flaws can affect significantly the surfaceproperties of adsorbents. When target substances are in the very lowpressure range, adsorption takes place on the most active sites on thesurface or within very narrow pores. Adsorbency by a synthetic polymermaterial such as polyolefin, polyester, polystyrene and other suchmaterials in the functional form of fiber, film or fabric is one exampleof this substantial problem.

We have also found, as the boiling point or partial pressure of theundesired molecules or substances decreases, adsorption of the gaseoussubstance at a constant concentration become increasingly more difficultbecause there is no energetic reason to promote adsorption and thegaseous substances substantially remain in the vapor phase of the mobilefluid or the enclosed volume. Low partial pressure does not causeadsorption. The molecular interactions between the gaseous substance andinterfacial layer are dependent on the particular surface compositionand/or the pore structure. As a molecule in a vapor phase approaches asolid surface, a balance is established between the intermolecularattractive and repulsive forces. Further, many adsorbing materials, asbulk material or in a coating, can have a small residual charge presenton the surface or displays a separation of charges, i.e., a dipole,effect. Any such extant charge or dipole can inhibit the targetsubstance approach to a surface and prevent substantial adsorption onthe surface. For example, in many containers a low, but objectionable,concentration of an unwanted or target substance can accumulate and bemaintained in the container contents. A substantial need arises toovercome these energetic and surface effects and improve adsorbency ofmalodors.

The compositions that can adsorb in static condition and obtainsurprising adsorption in dynamic conditions include a source of a ferric(Fe(III) iron) compound and a polyethylenimine (PEI). The PEI can befree of substituent groups on the nitrogen or carbon atoms of themolecule. The adsorbent composition can comprise a Fe(III) compound anda PEI compound or a Fe(III) compound and a PEI compound in at least amonolayer coating. This composition can successfully overcome thenatural tendency of such materials to prevent or avoid adsorption. Theadsorbent materials can remove, preferably, for example atconcentrations less than 15 ppm, of unwanted or target substances from astatic or dynamic gaseous or vapor phase.

Improved adsorbency in both dynamic and static mode is derived from anadsorbent comprising a combination of materials that can adsorb unwantedor target substances at low concentration. A removal compound orstructure (an adsorber) with reduced charge effects and high surfacearea can obtain functional adsorbency for low substance concentrations.The structural material can contain the adsorbent composition as acomponent or the adsorbency can be obtained from a coating on asubstrate. The substrate can be made of a natural or synthetic materialmade with thermoplastic materials that can be used in the form of bulkpolymer in a film, fiber, web, woven fabric, non-woven fabric, rigidsheet, cellulosic packaging and other such structures including orsurrounding the enclosed volume.

A first aspect comprises an adsorbent, adsorbant layer or coatingcomprising a Fe(III) compound and a PEI compound.

A second aspect comprises a polymer comprising a major portion of apolymer mass and an effective amount of a adsorbent, adsorbant layer orcoating comprising a Fe(III) compound and a PEI compound.

In a third aspect structure can comprise a film or fiber and a coatingof an adsorbent comprising a Fe(III) compound dispersed in a adherentpromoting PEI compound.

In a fourth aspect, this adsorbent layer or coating can be made from asolution or suspension of a major proportion of a solvent or liquidmedium and an adsorbent comprising Fe(III) compound and a PEI compound.The solution or suspension can comprise a liquid aqueous medium and canalso comprise a mixed liquid aqueous/non-aqueous medium.

Lastly, in a fifth, a non-woven article or a shaped object or othercommon polymer form of product can have an effective amount of anadsorbent, adsorbent layer or coating comprising a Fe(III) compound anda PEI compound. These include a container, a woven or non-woven fabricarticle, a sachet or other product format.

The adsorbency can be used in a woven or non-woven or a containerstructure to reduce the concentration of unwanted or target substances.The adsorbent compositions can be a compound of the structure or can beat least a monolayer coating. The adsorbent of the invention istypically used in the context of a dynamic or moving fluid or in astatic enclosed volume, also known as an enclosed ambient vapor phasethat contains the adsorbent of the invention and the unwanted or targetsubstances at a concentration that is not desirable. The concentrationshould be reduced to below detectable or human sensed limits. Often thelowest possible concentration is desired. Since the contact time indynamic mode is shorter, obtaining adsorption in dynamic conditions ismade more difficult than experienced in static conditions.

The thermoplastic material contains an active adsorbing composition, ora coating thereof, having a certain defined minimum surface area.Minimum coated thermoplastic surface area is 0.1 m²·gram⁻¹ that usesabout a 2 to 50 μm fiber diameter fiber. The minimum surface areaassociated with the Fe(OH)₃ is about 0.5 m². See FIG. 2 for therelationship between fiber surface area and fiber diameter. A briefinspection of FIG. 2 shows that as the fiber diameter of the nonwoven isreduced to less than 4μ and in particular less than 2μ, the surface areaof the nonwoven increases rapidly. As the surface area increases, thefiber coating process and coating solution solids change to achieveuniform surface coating. Accordingly while fibers in the range of 2 to20μ can be effectively coated and while fibers of the smaller diametercan also be coated the fibers in the range of 1 to 50 μ, 2 to 20μ aremost readily coated and used in manufacture.

The material can have the adsorbent blended or dispersed into the bulkpolymer extending to the surface or in a surface coating of one or morecoated layers. The surface of the polymer must expose a minimum amountof the Fe(III) and PEI compound to effectively adsorb.

Depending on context, virtually any, gas or vapor phase, chemicalspecies or mixtures thereof can be an “unwanted or target substance”existing in a dynamic flow or in an enclosed volume or enclosed ambientvapor phase. Such substances can be present at a concentration of atleast 5 ppb; about 15 to 0.01 ppm; 5 to 0.01 ppm; 1 to 0.01 ppm or lessthan 0.5 to 0.01 ppm (concentration based on the total volume) and canbe the subject of the adsorption characteristics of the invention toreduce the concentration to a undetectable limit, a limit that is notoffensive to humans or to a limit that does not produce a biologicalresponse. As the concentration of these materials in the vapor isreduced, and as the dynamic contact time is reduced to less than 1second, the difficulty of absorbance increases.

The term “dynamic stream” is a fluid (gaseous or vapor) stream flowing aflow rate of at least 1 liters·min⁻¹ (16.6 cm³·sec⁻¹) through a layer oraperture. “Gas” implies a uniform phase or blend of gaseous components.“Vapor” implies a dispersion of small particulate (often liquiddroplets, solid particles, and combinations of these) materials in a gasphase.

The term “enclosed volume or enclosed ambient vapor phase” means astatic atmosphere containing a target substance is held in a volume withlittle or no flow.

The unwanted or target substances can exist in the enclosed volume orenclosed ambient vapor phase as a gas, vapor or dispersion of a liquiddroplet or solid. These substances often are malodors, irritants, oroffensive or inoffensive odor compounds.

“Dynamic removal” an adsorption followed by absorption include areduction in concentration of unwanted substance by at least a flow ofat least 1 liters·min⁻¹ (16.6 cm³·sec⁻¹) through a layer or aperture ata contact time of less than 1 second.

A thermoplastic composition comprising a thermoplastic polymer materialwith an active adsorbent composite can maintain a substantially neutralbalance of negative charge and positive charge material and can enhancethe adsorption of compositions onto or into the adsorbent material. Thecombination of Fe(III) species and PEI in these surfaces obtainsexcellent adsorbency. The compositions can also contain materials thatcan enhance or increase the surface area of the surface of thethermoplastic articles. An increased surface area and favorable poresize can increase the adsorption of compounds into the adsorbingmaterials. The thermoplastic material of the invention can be used in avariety of end uses including webbing layers or structures, protectivebarrier fabrics or articles, filtration units, face masks, storage bags,garbage bags, deodorizing materials and other such applications. Oneparticularly useful application is a face mask having one or more layersthat can remove malodors from breath. Such malodors arise from H₂S andorgano sulfur compounds.

The term “fiber” is used in its conventional meaning. The term “fabric”typically means both woven and nonwoven webs including materials ofvarious thicknesses, lengths, widths and compositions. Products includefabrics made typically from the thermoplastic fibers of the inventionbut can also be made of other fabrics such as cellulosics, linens, andothers. The applications for the materials of the invention can be usedin face masks, tissue, wipes, towels, clothing, furniture, automotiveand other transportation, filtration for industrial or consumerapplications. The fibers used in yarn or other nonwovens as described inthe invention typically means fibers having relatively small fiberdiameters. Such a diameter is generally ranging from about less than 1micron to as much as 100 microns. Often such fibers have a diameter fromabout 1 to about 50 microns. Once assembled, a final product can includeone or more of the structures disclosed above. The fiber can be combinedin a thermoplastic layer, two or more thermoplastic layers can becombined, and a woven fabric can be combined with a nonwoven fabricwhich can also be laminated onto a film or other such structure. Thereare a variety of combinations or combinations of the structures of theinvention that can be made without departing from the spirit and scopeof the invention.

The term “container” in the context of the invention is used in itsconventional meaning. The container can comprise a structure surroundinga void or volume and the container can contain the adsorbent materialsor a coating thereof. The container, for example, can surround a volumecontaining a small piece of adsorbent material held within thecontainer. Such containers can include virtually any article that canenclose the vapor phase or atmosphere of the invention. The containerscan be made from virtually any materials including cellulosics,plastics, thermosets, metals and other conventional packaging materials.The containers can obtain virtually any geometric shape or dimension.The internal volume of the container can range from as small as 10millimeters to more than 100 liters, but typically ranges from about 100millimeters to 4 liters in size. The configuration of the container canbe virtually any configuration, including containers made from flexibleplastic, rigid and semi-rigid sheet, blow molded plastic bottles, foldedand glued paperboard materials, plastic and cellulosic envelopes andother container configurations.

FIG. 1 is a cross section of a test cell.

FIG. 2 is a graph representing the change is surface area of fiber asfiber diameter changes.

The adsorptive composition comprises a source of ferric iron includingFe(III)), a ferrate salt or Fe(OH)₃ combined with a polyalkylenimine(PEI) on a surface. A polymer composition can be modified by includingan effective amount of adsorbent onto the polymer mass.

Adsorbent Compositions Solids Content on the Composition

First Adsorbent Second Adsorbent Third Adsorbent Embodiment EmbodimentEmbodiment Components (Wt. %) (Wt. %) (Wt. %) Polyethylenimine 1.0-8015-65 20-60 Fe(III) 1.0-85 15-70 20-65 Compounds Optional Silica — — 1-30 Optional CD —  1-10 —

Polymer Compositions on the Total Polymer Composition

First Polymer Second Polymer Third Polymer Embodiment EmbodimentEmbodiment Components (Wt. %) (Wt. %) (Wt. %) Polymer  75-98  80-9585-95  Polyethylenimine 0.1-35 0.5-30 1-20 Fe(III) 0.1-35 0.2-30 1-20Compounds Optional 0.1-10 0.5-5   Silica/CD

Coating on Polymer Compositions on the Coated Material

First Second Third Embodiment Embodiment Embodiment Components (Wt. %)(Wt. %) (Wt. %) polymer  75-98  80-95  85-95 Polyethylenimine 0.1-10 1-9  2-8 Fe(III) 0.1-15 0.2-10 0.3-9 Compounds Optional Silicate 0.1-100.5-5 Optional CD 0.1-10 0.5-5

The adsorptive compositions can be in the form of a layer or coating andcan also contain a silica, a CD (cyclodextrin), a substitutedcyclodextrin (substituted CD) or a polymer with pendent CD moiety. Thesematerials with the adsorbent and optional components can be coated andlaminated into a variety of useful films, sheets, fibers, nonwoven webs,monolithic structures, or other shapes using conventional processingtechnology. These useful forms can be incorporated into a containerconfiguration.

Virtually any chemical species that can form a gas or vapor can be anunwanted or target substances. The unwanted or target substances canexist in a mobile fluid, gaseous stream or liquid or in an enclosedvolume or enclosed ambient vapor phase as a gas, vapor or dispersion ofa liquid or solid. These substances often are malodors, irritants, oroffensive or inoffensive odor compounds. Such compound chemical familiesinclude hydrocarbons C₃₊ alcohols or acids, sulfur compositions, amines,and can include alkanes, alkenes, alkynes, alkane thiols, alkylsulfides, alcohols, aldehydes, amines, carboxylic acids, ethers, andketones. Non-limiting example compounds include H₂S, methanethiol,ethanethiol, 1-propanethiol, 2-propanethiol, 2-butanethiol, carbonylsulfide, methyl allyl sulfide, methyl sulfide, dimethyl disulfide,dimethyl trisulfide, ethyl sulfide, methyl propyl sulfide, allylmercaptan, formic acid, formaldehyde, acetaldehyde, acrolein, diacetyl,dimethyl ether, diethyl ether, methylamine, dimethylaminetrimethylamine, ethylmethylamine, butylamine, cyclopropylamine, methane,ethane, propane, butane, ethylene, acetylene, propylene, 1-butene,2-butene, allene, isobutene, 1,3-butadiene, 1-butyne, 2-methylpropene,2-methyl-2-butene, cyclopropane, cyclobutane, methylcyclopropane andothers. Many of these malodors are present in breath associated withhalitosis.

Such substances can be present at a concentration of at least 5 ppb orabout 15 to 0.010 ppm (10 ppb) and can be the subject of the adsorptioncharacteristics of the invention to reduce the concentration that cannotbe sensed by humans or to a limit that does not produce a biologicalresponse. An offensive limit refers to the limit which is objectionableor unpleasant to an individual to sense the unwanted or targetsubstances. A limit that can produce a biological response refers to theamount that a pheromone or gaseous hormones such as ethylene can produceits desired result in a biological organism.

Polyethylenimine, used as an adsorbent, is a polyamine made bypolymerizing the cyclic monomer ethylene imine. The typical polymer cancontain primary terminal (—NH₂) groups, secondary (—NH—) amine groupswithin the polymer and in a chain branch and tertiary amine groups at abranch point. Linear polyethylenimines (PEIs) contain primarilysecondary amines with terminal primary amine groups. Branched PEIscontain primary, secondary and tertiary amino groups. The linear PEIsare solids at room temperature where branched PEIs are liquids at allmolecular weights. Linear polyethylenimines soluble in hot or coldwater, at low pH, in methanol, ethanol, or chloroform and is insolublein benzene, ethyl ether, and acetone. Polyethylenimine (CAS REGISTRYNUMBER 09002-98-6) is represented by the following general formula:

H(—NHCH₂CH₂—)_(x)NH₂; or

H(NA¹CH₂CH₂—)_(x)(NA¹ ₂CH₂CH₂—)_(x)(—NA¹CH₂CH₂—NH)_(x)H;

-   -   wherein each A1 is independently hydrogen, an alkoxy group or a        linear or branched polyethylenimine group and wherein each x is        independently from 5 to 20,000.

Polyethylenimine has an average molecular weight from about 500 to about1,000,000; preferably from about 2,000 to about 800,000; more preferablyfrom about 10,000 to about 750,000; and most preferably from about50,000 to about 750,000. Non-limiting examples of additional materialsinclude: epichlorohydrin modified PEI, ethoxylated polyethyleneimine,polypropylenimine diamine dendrimers,poly(1,2-dihydro-2,2,4-trimethylquinoline), andpoly(dimethylamine-co-epichlorohydrin-co-ethylenediamine).

The preferred Fe(III) compound useful in the construction comprises aferrate salt or ferric hydroxide Fe(OH)₃ also known as the ferric oxyhydroxide as a result of unique iron stoichiometry. Typically theFe(III) compound is combined with a polymer and is coated into anadsorbent layer and after coating and final assembly, the Fe(III), istypically converted into ferric hydroxide. A variety of sources of ironIII (Fe(III)) compounds can be used to form the active adsorbentmaterials.

The source of Fe(III) can be any iron-providing material, which caninclude carbonyl iron, iron salts, chelated iron, encapsulated iron,iron complexes, and mixtures thereof. Illustrative sources of Fe(III)contemplated by this invention include any of the ferric halides such asFeCl₃, ferric citrate, ferric nitrilotriacetic acid (Fe(III)-NTA),Fe(OH)_(e), ferric ammonium citrate, Fe(NO₃)₂, Fe(SO₂)₃, ferric oxidehydrate, ferric ammonium sulfate, ferric sodium citrate, ferric sodiumedetate, ferric acetate, ferric phosphate, ferric pyrophosphate, ferricfumarate, etc. Ferrous salts can be used if oxidized to Fe(III) beforeor after coating including ferric succinate, ferrous hydroxide, ferrousnitrate, ferrous carbonate, ferric sodium pyrophosphate, ferrictartrate, ferric potassium tartrate, and organo-ferric compounds.

Preferred sources of Fe(III) is selected from the group consisting offerric hydroxide, alkali metal ferrate, ferric chloride, ferric citrate,ferric nitrate, ferric nitrilotriacetic acid, powered ferricoxyhydroxide, other similar iron salts, and mixtures thereof.

A number of iron compounds in the ferric form, can remove malodors suchas volatile sulfur compounds in an active in finely divided form on asubstrate. Testing has shown that a source of Fe(OH)₃ in combinationwith PEI provides a degree of dynamic removal not achieved in the pastchemistries. Removal directly related to the nature of the surfaceincluding particle size, morphology and surface area. The surface ofFe(OH)₃ combined with PEI has a better removal character than comparablecombinations of Fe₂O₃ and PEI.

In industrial applications, iron (III) chloride is used in sewagetreatment and drinking water purification. In these applications, FeCl₃in slightly basic water reacts with the hydroxide ion to form a floc ofiron (III) hydroxide, or more precisely formulated as FeO(OH) known asferric oxide hydroxide.

Fe³⁺+4OH⁻→Fe(OH)₄ ⁻→FeO(OH)₂ ⁻.H₂O

A number of species are dubbed iron(III) oxide-hydroxide. Thesechemicals are oxide-hydroxides of iron, and may occur in anhydrous(FeO(OH)) or hydrated (FeO(OH).nH₂O) forms. The monohydrate(FeO(OH).H₂O) might otherwise be described as iron(III) hydroxide(Fe(OH)₃), and is also known as hydrated iron oxide. The active ferrichydroxide is a highly porous (mesosphere with a micropore volumeapproximately 0.0394+/−0.0056 cm³·g⁻¹, mesopore volume approximately0.0995+/−0.0096 cm³·g⁻¹) adsorbent with a BET surface area of 235+/−8m²·g⁻¹.

Iron(III) oxide-hydroxide can be obtained by reacting ferric chloridewith sodium hydroxide, potassium hydroxide or sodium bicarbonate intypically aqueous solution:

FeCl₃+3NaOH→Fe(OH)₃+3NaCl

FeCl₃+3KOH→Fe(OH)₃+3KCl

FeCl₃+3NaHCO₃→3NaCl+Fe(OH)₃+3CO₂

Some amount of Na⁺, K⁺, or Na Cl salt remains in the coating as a resultof these synthesis charateristics.

Alternatively, redox reactions of potassium ferrate (K₂FeO₄) producerust-like iron oxides which are environmentally innocuous and have beendescribed as a ‘green oxidant’. K₂FeO₄ is reactive as indicated by thefact that it decomposes in contact with water evolving oxygen andforming ferric hydroxide:

4K₂FeO₄+10H₂O→3O₂+4Fe(OH)₃+8KOH

Optionally, the construction can contain a CD compound or one or more ofthree forms of amorphous silica-silica gel, precipitated silica andfumed silica.

The particle size of the preferred materials range from about 0.001 to10³ or 0.050 to 700 microns and the preferred materials have a surfacearea that ranges from about 60 to 750 m²·gm⁻¹ or 200 to 1,000 m²·gm⁻¹.The compositions of the invention are often prepared by dispersing theFe(III) compound and polyethylenimine materials into a polymer or into acoating liquid. In one embodiment, the adsorber can be used with a CD orwith a silica materials for the purpose of introducing a relatively highsurface to the Fe(III) polyethylenimine material surface.

Silica particles can be used to enhance the surface area of thematerials of the invention. In particular, silica gel particles that arepreferred for use in the invention are relatively small particle sizematerials having large surface areas per gram. Synthetic amorphoussilica (CAS #7631-86-9), a form of silicon dioxide (SiO₂) ismanufactured, thus differentiating it from naturally occurring amorphoussilica, e.g. diatomaceous earth. As a manmade product, it is greaterthan 95% pure amorphous silica whereas naturally occurring amorphoussilica also contains crystalline forms of silica. Amorphous silica canbe further divided into two forms that are characterized by theirdistinct manufacturing processes—wet process silica (CAS #112926-00-8)which includes precipitated silica and silica gel, and thermal processsilica (CAS #112945-52-5) which includes fumed or pyrogenic silica.Fumed silica is essentially non-porous whereas precipitated silicacontains some micropores (>0.3 μm) and silica gel is highly porous andcontains macro-, meso-, and micro-pores offering a pore size range from0.0001 to 1 μm . Pore size is defined as the pore width measured as thediameter of the cylindrical pore or distance between opposite walls ofthe slit. Fumed silica is commercially manufactured by DegussaCorporation (Areosil) and Cabot Corporation (Cab-O-Sil). Silica gel ismanufactured by W.R. Grace (Davisil) and Merck Chemicals.

Cyclodextrin can be used as an unmodified material, as a substitutedmaterial or as a CD grafted polymer material. CD is a cyclic oligomer ofα-D-glucose formed by the action of certain enzymes such as CDglycotransferase (CGTase). Three CDs (alpha, beta, and gamma) arecommercially available consisting of six, seven, and eight α-1,4-linkedglucose monomers, respectively. The most stable three-dimensionalmolecular configuration for these oligosaccharides is a toroid with thesmaller and larger opening of the toroid presenting primary andsecondary hydroxyl groups. The specific coupling of the glucose monomersgives the CD a rigid, truncated conical molecular structure with ahollow interior of a specific volume. The CD can be used as asubstituted CD or a polymer with pendent CD moiety. CD molecules haveavailable for reaction a primary hydroxyl at the six position of theglucose moiety, and at the secondary hydroxyl in the two and threepositions. Because of the geometry of the CD molecule, and the chemistryof the ring substituents, all hydroxyl groups are not equal inreactivity. However, with care and effective reaction conditions,substantially dry CD molecules can be reacted to obtain a substituted orgrafted CD. A CD with selected substituents, i.e., substituted only onthe primary hydroxyl or selectively substituted only at one or both thesecondary hydroxyl groups can also be grafted if desired. Directedsynthesis of a derivatized molecule with two different substituents orthree different substituents is also possible. These substituents can beplaced at random or directed to a specific hydroxyl. These substituentsmay be chosen such that they the site of the grafting reaction. Forexample, alcohol derivatives (e.g., hydroxyethyl and hydroxypropyl) andamino derivatives of CD can be reacted with a substituent on a polymerbackbone to make a grafted CD.

A preferred preparatory scheme for producing a substituted CD materialinvolves reactions at the primary or secondary hydroxyls of the CDmolecule. It is meant that a hydroxyl functionality of the CD reactswith a substituent forming reactant. The formation of an ester or etherbond on either the primary or secondary ring hydroxyls of the CDmolecule involve well-known reactions. For the purpose of this patentdisclosure, the term “degree of substitution (D.S.)” for the CD meansthe statistical average number of substituents on each glucose moiety ofthe CD ring.

The invention can also include a polymer with pendent CD moiety.Commercial polymer functionalization can be achieved, for example, usingsolution, melt and solid state routes known in the art. The processcovalently bonds monomers onto polymers generally. Polyolefin polymerscan be used including, for example, copolymers of olefins with othermonomers, such as vinyl monomers, which predominately constitute theolefin portion. Polyolefins useful in this disclosure include, forexample, poly(ethylene) or PE, poly(propylene) or PP,poly(ethylene-co-propylene) or PEP, ethylene/methyl acrylate copolymer,ethylene/ethyl acrylate copolymer, ethylene-α.-octene copolymer,ethylene-butene copolymers, and like polymers and copolymers. Thepolyolefins can be functionally modified with unsaturated compounds suchas unsaturated anhydrides and carboxylic acids. Additionally, there canbe modified terpolymers of, for example, ethylene-acrylate (ethyl orbutyl)-maleic anhydride, ethylene-methyl acrylate-glycidyl methacrylate,and like polymers. In embodiments, any packaging grade of a vinylpolymer can be used. The modified polymers of the invention can bederived in some embodiments from a polymer having a melt index of about0.7 to 1,800 g·10 min⁻¹. In other embodiments, the modified polymers ofthe invention can be derived from a polymer having a melt index of about1 to about 1,200 g·10 min⁻¹.

Functionalized polyolefins can be used with the coatings of theinvention or blended with the CD pendant polymers. Functionalizedpolyolefins, have extensive industrial applications such as extrusion orcoextrusion tie resins in multi-layer films and bottles for the foodindustry, compatibilizers for engineering polymers and plastic fuel tanktie resins for the automotive industry, flexibilization andcompatibilization of halogen free polymers for cables, for fillermaterials used in roofing construction, and like applications.Functionalized polyolefins useful in the present disclosure include, forexample, maleated polyethylene and polypropylene (OREVAC and LOTRYL fromAtofina Chemicals Inc. of Philadelphia, Pa., PLEXAR and INTEGRATE resinsfrom Equistar Chemicals L.P of Houston, Tex., FUSABOND resins fromDuPont Co. of Wilmington, Del., OPTM resins from Manas of Ankara,Turkey, ADMER resins from Mitsui Chemicals of Rye Brook, N.Y., andEXXELOR from Exxon/Mobil Corp. of Irving, Tex.), maleic anhydridefunctionalized ethylene vinyl acetate copolymers (EVA-MA, such as OrevacEVA-MA from Atofina or Fusabond C series EVA-MA from DuPont); EPDM (suchas ethylene-propylene-butadiene or ethylene-propylene-1,4-hexadienepolymers) ethylene/1-butene copolymers, ethylene/1-hexene copolymers,ethylene/1-octene copolymers, ethylene-n butyl acrylate-maleic anhydridecopolymers, ethylene-ethylacrylate-maleic anhydride terpolymers, orcopolymers of ethylene and glycidyl methacrylate. Other polymers, thatare not olefinic, can also be employed in embodiments of the invention.For example, styrene-maleic anhydride (SMA) copolymers are aparticularly useful group of reactive copolymers. SMA copolymers areavailable as, for example, Hiloy SMA copolymers from A. Schulman Inc. ofAkron, Ohio, Prevex, SMA from General Electric Co. of Fairfield, Conn.and Dylark SMA from NOVA Chemicals of Calgary, Alberta Moon Township,Pa. Ethylene-propylene-1,4-hexadiene polymer can be represented as:wherein x, y and z can be selected to obtain, for example, about 70 to90 wt % ethylene, about 10 to 30 wt % propylene and up to about 5 wt %1,4-hexadiene R₁ and R₂ may be similar groups, H, or end groups.

The copolymerization of styrene with maleic anhydride to form SMAcopolymer provides a material with a higher glass transition temperaturethan polystyrene and is chemically reactive as it provides maleicanhydride functionality. SMA copolymers are often used in blends orcomposites where interaction or reaction of the maleic anhydrideprovides for desirable interfacial effects. SMA is utilized in theautomotive industry for the injection molding and thermoforming ofinterior parts. The superiority of SMA over polystyrene is due to itshigher heat deflection temperature, which is required for automotiveuse. SMA copolymers have also been extensively used as binder polymersdue to the reactive maleic anhydride moieties, which can easily befunctionalized with a group or groups to provide tailorable surfaceenergy and chemical compatibility. For example, Keil et al., U.S. Pat.Nos. 5,576,145, 5,698,370, and 5,773,518 disclose an SMA based binderpolymer in which the maleic anhydride residues are mono-esterified tobetween about 50 and about 65 mole percent of an alkyl, aryl,cycloalkyl, alkaryl, or arylalkyl alcohol having a molecular weightgreater than 100 as a means of providing interlayer adhesion between twoincompatible polymers.

Another useful polymer that can be grafted with CD to form a CD graftedpolymer of the invention is polypropylene. Commercially, maleicanhydride bonded to polypropylene is available, for example, fromHoneywell Performance Products of Heverlee, Belgium or the Sigma AldrichCompany of St. Louis, Mo. However, maleic anhydride is also easily addedto polypropylene, e.g. in an extrusion reaction by adding maleicanhydride to a molten extrusion stream of polypropylene. In suchreaction schemes, CD can advantageously be added further down in theextrusion path, where it can react with the maleic anhydride groups onthe modified polypropylene. The general reaction scheme of incorporatingmaleic anhydride into polypropylene using a radical source such ashydrogen peroxide is shown below.

Polymer with pendent CD compositions of this disclosure may be preparedusing, for example, reactive extrusion by feeding a dry CD, orderivative thereof, (<0.10% moisture), a functionalized polyolefin andoptionally a second polyolefin, into an extruder at temperatures suchthat the CD reacts with the functionalized polyolefin as the moltenpolymer and CD are transported through the extruder to form a reactionproduct containing. One class of useful polymers is polyolefins,including polyethylene, polypropylene and related copolymers andterpolymers. In some embodiments, a mixture of a cyclodextrin (CD), asubstituted CD or a polymer with pendent CD moiety can be used orblended with an unmodified polyolefin resin. In these embodiments, theunmodified thermoplastic resin can have a melt index of about 0.5 to1800 g·10 min⁻¹, and the modified polymer can be derived from a polymerhaving a melt index of about 0.7 to 1,500 g·10 min⁻¹, or about 1 to1,200 g·10 min⁻¹. Another class of useful polymers is polyesters.

Air flow rate past a layer or through a composite can be in the range of1 to 50 liters·min⁻¹, 5 to 20 liters·min⁻¹ (16.6 to 833.3 cm³·sec.⁻¹ or83 to 333 cm³·sec.⁻¹) depending on application. In a face mask thevolume is an inspiration/expiration volume (the lung volume of menversus that of women) and normal breathing or rapid breathing results ina contact time on the fiber of about 0.1 to less than 0.01 sec. andabout 0.05 to 0.01 seconds. Normal static or dynamic H₂S scrubbingprocesses require several minute contact times. Some PEI coatings onsilica-monoliths have contact times in the range of 0.1 to 0.2 sec basedon linear flow. The adsorbent/adsorbent structures disclosed can beeffective with extremely low H₂S to Fe(OH)₃/PEI/fiber surface contacttime. Using a static test instead of a dynamic test, most coatings willprovide some removal depending on surface area/geometry andconcentration of malodor, Fe(III) and PEI. In a dynamic test, a ferratecompound with a cation and a ferrate anion (FeO₄)⁻² such as sodiumNa₂(FeO₄) or potassium ferrate K₂(FeO₄) or Fe(OH)₃ in combination withPEI obtains enhanced removal. Ferrate compounds are converted intoFe(OH)₃ in the mask layers.

A useful construction can contain a substrate with an activeconcentration of the Fe(III) and PEI in the substrate or the substratecan contain a coating of the Fe(III) and PEI. Such a substrate can be afiber, film, fabric (woven or non-woven) sheet, rigid or semi rigidlayer or other article. The construction can use a single ormultilayered assembly having an adsorbent as a compound of theconstruction or as a removal layer. A removal layer with an activechemistry capable of removing malodorous substances from a dynamicstream passing past or through the construction can improve adsorption.

The removal layer can be made by either blending the adsorbent with thesubstrate material or by coating a structure or substrate with asolution of the Fe(III) compound and the polyethylenimine. The substratecan be any material in the form of film, fiber, sheet, semi-rigid orrigid sheet, containers, non-woven or woven fabrics, etc. The substratecan be a natural or synthetic polymer.

Examples of useful substrate materials are natural materials orsynthetics such as non-woven polyesters; synthetic nonwovenpolypropylene and natural woven cotton interlock materials. Substratematerials can be selected from the group consisting of: polyolefins(e.g., polyethylene, polypropylene), polylactic acid, polyesters (PET,CPET & rPET), nylons, acetates, nylon, polyethylene, polyesters,polypropylene, polystyrene, ethylene vinyl acetate copolymers,polyurethanes, poly-α-olefins such as polybutadiene and poly α-octene,and polyamides such as nylon-6 and nylon-6,6, polyureas, polycarbonates,polyethers, polyketones, poly(vinyl chloride), fluoropolymers, andsilicone polymers are commonly used polymers in forming useful articles.Similarly, many commercially useful copolymers, terpolymers, and thelike can be used. For example, polyesters, PLA polymers and copolymers,acrylonitrile-butadiene-styrene (ABS), poly(ethyleneoxide)-co-(propylene oxide), ethylene-vinyl acetate copolymers,poly(ether-ether-ketone) and the like are useful copolymers andterpolymers for various end use applications. Any other polymer andcopolymer capable of being formed into film or fibers can be used.Natural fibers comprising cotton or cellulose capable of being formedinto a sheet or woven and combinations thereof.

Polyesters are a generally useful class of polymers from which manycontainers, nonwoven fabrics, and various other articles are made. Usesof polyesters include applications set forth in co-pending U.S. patentapplication Ser. No. 10/163,817. One useful polyester material that canbe incorporated into a blend with, or topically coated with theinvention is polylactic acid, or polylactide (PLA). PLA is abiodegradable, thermoplastic, aliphatic polyester derived from renewableresources and having a general repeat unit of —CH(R)—C(O)—O—. It is mostcommonly formed from starting materials such as corn starch orsugarcane. Bacterial fermentation is used to produce lactic acid, whichis oligomerized and then catalytically dimerized to make a lactidemonomer for ring-opening polymerization. It can be easily produced in ahigh molecular weight form through ring-opening polymerization usingmost commonly a stannous octoate or tin (II) chloride ring openingcatalyst. PLA can be processed like most thermoplastics into fiber (forexample using conventional melt spinning processes) and film.NatureWorks LLC, a wholly owned subsidiary of Cargill Corporation,produces PLA under the trade name NatureWorks polymer. Other companiesfrom which PLA can be obtained include Toyota (Japan), Hycail (TheNetherlands), and Galactic (Belgium). Because it is biodegradable, PLAcan be employed in the preparation of bioplastic for such articles asfood packaging, loose fill packaging, and disposable containers. PLA canalso be made into fibers.

In addition to the adsorbent, the substrate can include, in variousembodiments, a mixture of natural and synthetic fibers; reactive fibers;scavenging fibers (e.g., zeolite, activated charcoal, and likescavengers); biodegradable polymer materials such as polylactic acid; areduced basis weight; or combinations thereof. The containers of thedisclosure may have a range of properties imparted to them, such asbreathability; stretchability; shape or body-conforming capability;cloth-like aesthetics and feel; rigidity; high strength; transparency oropacity; a smooth or patterned surface; and the like.

The compositions are directed to reducing the concentration of unwantedor target substances within an enclosed atmosphere or vapor phase. Suchan atmosphere or vapor phase is often held within and substantiallysurrounded by a container. The important characteristic of the containerof the invention is that it encloses the atmosphere or vapor phase ofthe invention and can be made from or combined with the compositions ofthe invention for the purpose of reducing the concentration of theunwanted or target compositions of the invention from the enclosedatmosphere or vapor phase. In this regard, in the manufacture of thecontainers of the invention, the compositions of the inventions can beincorporated into the materials from which the containers are made. Forexample, a PET beverage container can be made from a thermoplasticpolyester that contains the Fe(III) and PEI compounds and the othermaterials of the invention that can reduce the concentration ofundesirable or target substances that can form within the vapor phaseheld within the PET plastic container. Alternatively, such a containercan be made by coating the interior of the container with the adsorbentcomposition.

Alternatively, an insert can be used by placing it into the interior ofthe container. The insert material can be made from the composition ofthe invention or coated by the compositions of the invention and as longas the insert can adsorb and is held within the internal structures ofthe invention, the compositions of the invention can reduce theconcentrations of the unwanted or target composition. The insertcomprising the compositions of the invention or a material coated withthe compositions of the invention can take a variety of embodiments. Forexample, a flexible food wrapper can be coated with the compositions ofthe invention. Such a wrapper can be made from thermoplastic materialsor from cellulosic or paper derived compositions. Such wrappers can beused as a primary wrapping structure or can comprise an internalenvelope containing a food product, for example, as used in an internalenvelope for breakfast cereal. The thermoplastic compositions in theinvention can be formed into virtually any shape or configuration usefulin packaging food and the coating compositions of the invention can becoated on virtually any container surface useful in packagingtechnologies.

Another embodiment of the invention is a porous nonwoven (spunbond ormeltblown) or woven fabric comprising the adsorbent composition. Such afabric can be used to continuously reduce unwanted or target substancesfrom a dynamic stream or from the closed atmosphere of a package.

The compositions of the invention can be used in the form of sachets.The sachets can contain the compositions of the invention in the form ofparticulate film or fiber.

Alternatively, the sachets can be made of fiber or film made from thecompositions of the invention and can be formed to contain the materialsof the invention. The sachets of our invention comprise hollow containerfabricated from permeable, porous or non-porous materials. The containercan take any form including but not limited to an envelope, a sheet, anon-woven or woven format. The containers can be closed using anyclosure technology including adhesive closure, heat seal technology orsewing. The porous materials are porous to the target adsorbent of theinvention. The sachets of our invention are fabricated from permeable orporous materials that can be formed into enclosures. The fabric,non-woven or sachets can be made of natural fibers or from syntheticthermoplastics in the form of woven fabric, non-woven or film. Theadsorbent article can also be fabricated from non-porous materials ifthe walls have discrete openings so that adsorbent may pass therethrough as they arise.

In certain embodiments, the present disclosure provides a containerarticle comprising a film of the present invention containing theadsorbent or having an adsorbent coating. Such a film preferably has athickness of 500 μm or less and more preferably 0.5 to 400 μm. Incertain thin-film applications and/or handling, the thickness of thefilm is preferably 5 to 200 μm and more preferably 10 to 100 μm. Thefilm can comprise a thermoplastic polymer composition comprising a blendof a polyolefin resin and a chemically-modified polyolefin resin or ablend of thermoplastic resins (e.g., PE, PP, PET and polylactic acid(PLA)) and can be made using conventional methods. Flexible films aretypically melt extruded through a straight or circular die and can havethickness of, for example, from about 4 micrometers (μm) to about 200μm. The films may be extruded at much greater thickness, and thenstretched in one or two directions to a thin, uniform film.Post-extrusion stretching, uniaxial or biaxial, can also provideorientation of the molecular structure that can further enhance strengthand barrier properties of the film. Processes for extrusion andlaminating thermoplastic materials are described in U.S. Pat. Nos.3,400,190; 3,440,686; 3,477,099; 3,479,425; 3,476,627; 3,524,795;3,557,265; 3,583,032; and 3,365,750. Many coextruded structures are madeup of polyolefins such as polyethylene and polypropylene. Thesepolyolefins are useful for compositions of the invention. Low densitypolyethylene (LDPE) and linear low density polyethylene (LLDPE) resinshave been used extensively in coextruded structures for their toughnessand sealability. High density polyethylene (HDPE) resins are selectedfor their moisture barrier, stiffness and machineabilitycharacteristics. Polypropylene (PP) is chosen for its ability, throughorientation, to provide clear machineable films with high impact andstiffness properties. Polyolefins can be combined with other resins toachieve multilayer functionality. Copolymers of ethylene-vinyl acetate(EVA), ethylene-αcrylic acid (EAA), and ethylene-meth acrylic acid (EMA)are regularly used as skin layers for their low-temperature sealingcharacteristics.

Semi-Rigid Films are produced by straight die melt extrusion orcalendaring. Multilayer structures can be, for example, a co-extrusionor an adhesive lamination. Typical thermoforming grade films can havethickness of, for example, from about 200 microns to about 1 millimeter.The coextruded sheet structures may be high-barrier packages.Polystyrene, polyester, polypropylene, and polyethylene are thepredominant structural materials used in co-extrusions for semi-rigidpackaging applications. Known co-extrusion structures for semi-rigidpackaging is described in U.S. Pat. Nos. 3,479,425 and 3,557,265.Structural resin selection is dependent on use requirements,co-extrusion processability, and container-forming considerations. Suchfilms can be heat softened and vacuum formed into tubs, pots, blisters,trays and punnets.

Rigid films can be made by, for example, extrusion, co-extrusion,profile extrusion, injection molding, compression molding, reactioninjection molding, injection blow molding, or any other thermalprocesses known in the art. Rigid structures typically have thicknessesgreater than 1 millimeter, and may have thickness of up to 2.0 cm oreven greater thicknesses. Many of these containers are of a monolayerstructure as the large wall thickness provides for an adequate barrier.Where a high barrier is required, multilayer structure techniques can beused. One such rigid structure is a storage unit, such as for storingfood, clothing, soiled items, household wastes, and the like. Suchstructures can be, for example, a diaper pail, a vegetable bin for arefrigerator, a reusable food container, a general storage bin, or agarbage container.

Composite Materials typically multilayer plastic structures can befurther extended with the inclusion of one or more plastic ornon-plastic materials. Materials that can be combined with plastics toform composites can be, for example, thermoset resin, aluminum, paper,felt, paperboard, nonwovens and like materials. The combination ofpaper, paperboard, foil, and thermoplastic polymers, can provide, forexample, a sealable high-barrier structure. Multilayer packagingstructures are described in U.S. Pat. Nos. 3,274,905; 4,720,039;5,829,669 and 6,244,500. Combining thermoplastics with paperboard canprovide hermetic, rigid composite structures, such as round, canisterand shaped composite paperboard cans, paperboard pails, fibercartridges. Common uses of such structures are, for example, powderedbeverages and infant formulas, cereal, coffee, snacks, nuts, cookies andcrackers, confectionery, spices/seasonings, nutritional supplements, andpet foods. In such applications, the compositions of the inventionprovide new packaging performance attributes for high barrier packages,particularly when used for foods that are susceptible to undesirablefood decomposition flavor and odor within the package.

Multifunctional packaging resins can be combined into one manufacturingstep using, for example, co-extrusion technology. Multilayer structuresare distinct coextruded layers of different polymers formed by asimultaneous extrusion of the polymers through a single die. Multilayerfilms produced by lamination or co-extrusion can offer an enhancement ofmany or all performance properties compared to monolayer films.Typically, a multilayer plastic film can incorporate compositions of theinvention into one or more layers, typically a layer exposed to theenclosed atmosphere depending on the desired functionality.

Coextruded multilayer structures can be divided into three categories:single-resin, unbalanced, and balanced. There can be, for example,multilayer films using only one polymer (AAA), unbalanced coextrudedfilms with combinations of two or more polymers (ABC), and balancedmultilayer structures with combinations of two or more polymers(A/B/C/B/A). Unbalanced structures typically combine a functional layerwith a heat-seal resin. Balanced structures generally have the sameheat-sealable resin on both the outside and inside surface of the film.

In certain embodiments, the present disclosure provides a containerarticle comprising a fabric. Such a fabric can be a portion of thestructure with the enclosed volume or enclosed ambient vapor phase. Thefabric comprising a woven or nonwoven web, the web comprising a fibercomprising a thermoplastic polymer composition comprising a blend of apolyolefin resin and a chemically-modified polyolefin resin or a blendof thermoplastic resins (e.g., PE, PP, PET and polylactic acid (PLA)).The article comprises a nonwoven web comprising a spunbond fabric, ameltblown fabric, an electrospun fabric, and combinations thereof.Examples of spunbond fabric and meltblown fabric are known in the art,and may be spun-bond-meltblown-spunbond (SMS),spunbond-meltblown-meltblown-spunbond (SMMS), and like permutations orcombinations. Other articles, such as a litter box, shoe box, foodstorage box or bin, laundry basket, or clothing box or bag mayadvantageously incorporate liners having compositions of the inventionincorporated therein. Further, the polyolefin used in disposable plasticgarbage bags, garment bags, diaper bags, vacuum cleaner bags, and thelike can also be made using polymer with an effective amount ofpolyolefin having covalently bonded CD. In embodiments, any of theabovementioned articles or components can be prepared or processed withany of the abovementioned processes or any of the following melt basedprocesses to form a desired article or component structure, andcombinations thereof, including: spunbond, meltblown, nanofiber, porousfilm, or co-form. In embodiments, any of the abovementioned articles orcomponents can also be prepared or processed with any of the followingstaple-based or natural fiber based processes or structures, andcombinations thereof, including: hydroentanglement, bonded-carded,needle punched, airlaid, wetlaid, and like processes and structures, orcombinations thereof.

Fiber in this disclosure refers to generally continuous lengths ofmaterials having a diameter of about 0.1 micron to 200 microns and about2 to 50 microns. Such fiber can be used as fluff, as a web, a woven ornon-woven fabric or as a composite material. The webs and fabricsfashioned there from can also comprise bicomponent fibers. Bicomponentfiber technology enables manufacturers to, for example: reduce cost;improve strength and softness; produce ultra-fine fibers; provideimproved loft, crimp, or both; and like process and productimprovements. One type of bicomponent fiber is a known material in whichthe fiber contains an amount of polymer having a relatively high meltingpoint and a second amount of a polymer having a relatively low meltingpoint. In the formation of a web or layer of a web, the fiber is heatedto a temperature such that the low melting point polymer can melt, fuseand bind the layer or web into a mechanically stable, unitary mass. Therelatively high melting point polymer component can provide mechanicalstrength and stability to the layer or web. Bicomponent fibers can thusallow the fabrication of thermally bonded webs, thus providingadditional strength, cohesiveness, and robustness of nonwoven webs madefrom them. Where such properties are desired, use of bicomponent fiberis often sufficient to impart these properties and no further binders orprocedures are required to provide the web with additional cohesiveness,strength, etc. Some embodiments of the invention may also comprisenanofiber. Nanofiber can be formed, for example, by electrospinning,where fibers are spun with diameters of from about 10 nm to severalhundred nm. The resulting fiber properties can depend on, for example,field uniformity, polymer viscosity, electric field strength, thedistance between nozzle and collector, and like considerations.

Web production methods useful for fiber and fabric preparation caninclude any other suitable method, such as extrusion. Co-extrusion,spunlace, porous film, co-form, bonded-carded, needle punch, airlaid,wetlaid, and like methods, or combinations thereof. Spunlace processing,also known as hydroentangling, involves mechanically wrapping andknotting fibers in a web through the use of high velocity jets of water.Spunlaced nonwovens work well for wipes because they are soft, strong,easy to handle, and provide good absorption. In embodiments, methodsuseful for fiber and fabric preparation can additionally include anyother suitable processing methods, for example, thermo-bonding, chemicalor resin bonding, and like methods. In some embodiments, fibers, fabricsand absorbent materials of the invention can include other suitablefunctional or performance additives or treatments, for example, anantimicrobial, an anti-static agent, a flame retardant, afluorochemical, a wetting agent, an ultraviolet stabilizer, a laminate,a binder or an adhesive, a hot melt adhesive, a filler, a silanecoupling agent, and like additives or treatments, or combinationsthereof. In embodiments, depending upon its disposition and purpose inthe fiber or final article, an additive can be included, for example, ina masterbatch, added directly to an extruder, applied topically to afiber or web surface, and like inclusion methods, or combinationsthereof. In embodiments, a binder or an adhesive can include, forexample, an acrylic, a hot melt, a latex, a polyvinyl chloride, apressure sensitive adhesive, a styrenated acrylic, styrene butadiene,vinyl acetate, ethylene vinyl acetate, vinyl acrylic, a melt-fusiblefiber, a partially meltable bicomponent fiber (e.g., PE/PP, PE/PET,specially formulated PET/PET), and like materials, or combinationsthereof.

The coatings can be made by contacting a surface such as a thermoplasticfilm, fiber, nonwoven etc., with a solution of both the Fe(III) compoundand the PEI.

The thermoplastic materials can be coated with aqueous or co-solventbased coating. Preferred co-solvents are benign liquid media such aslower alcohols, glycol, glycol ethers, glycol esters or aqueous media.Coatings are typically made by blending the coating components into theliquids to form a coating solution. The solution can contain the activeFe(III) material and PEI with conventional additives, co-solvents, dyes,etc. The coating solution can then be coated using conventional coatingstechnology including knife coating, roll coating, slot coating,saturation coating, flooded nip coating, rod coating, curtain coating,spray coating, gravure coating, etc.

Fe(III) or PEI compounds, or both, can be uniformly surface coated ontoa particulate to increase surface area such as on a silica particle oron to CD particles prior to grafting CD onto functionalized polyolefinby reactive extrusion. The Fe(III)/PEI coating and drying of theparticulate are carried out concurrently in a dryer providing heating ina controlled atmosphere. A stainless steel tumble dryer, jacketed withcirculating oil heating walls, and equipped with a liquid spray barrunning along the center of horizontal rotation of the dryer can be usedto spray the aqueous PEI coating solution onto the particulate inconstant motion. The vacuum lowers the boiling point of the water, whileparticle contact with the vessel walls provides fast heat input foruniform drying. This coating process prevents lumping, segregation andallows uniform PEI coating of the CD particles.

The compositions can be made with amounts of the components as shown inthe following tables.

Solvent Coating Compositions

First Second Third Embodiment Embodiment Embodiment Components (Wt. %)(Wt. %) (Wt. %) Solvent  40-99  70-95   75-90 Co-Solvent  0.1-20   1-15   2-10 Polyethylenimine 0.01-15 0.02-10 0.03-9 Fe(III) 0.01-15 0.02-100.03-9 Compounds

Aqueous Coating Compositions

First Second Third Embodiment Embodiment Embodiment Components (Wt. %)(Wt. %) (Wt. %) Water  40-99  70-95   75-90 Co-Solvent —   1-30    2-25Polyethylenimine 0.01-15 0.02-10 0.03-9 Fe(III) 0.01-15 0.02-10 0.03-9Compounds

The coatings can be continuous or partial coatings. The coatings can bemade on film, fiber, fabric (non-woven or woven), container, sheet orother polymer format. The coatings can have a thickness of about 0.5 to25 microns, 1 to 20 microns or 5 to 10 microns. The add-on amounts tonon-woven can be about 30 to 800 micrograms·cm⁻², about 50 to 600micrograms·cm⁻² or about 100 to 400 micrograms·cm⁻². The add-on amountsto fiber can be about 15 to 300 milligrams-gm⁻¹, about 25 to 225milligrams-gm⁻¹ or about 50 to 175 milligrams·gm⁻¹. The add-on amountsto container, film or sheet can be about 30 to 800 micrograms·cm⁻²,about 50 to 600 micrograms·cm⁻² or about 100 to 400 micrograms·cm⁻².

The adsorbent compositions illustrated above are normally dispersed insolvent, in aqueous medium, solvent and water or water with usefulco-solvents. The aqueous compositions are then applied to a substrate toreduce unwanted or target substances from an enclosed volume which thesubstrate is exposed. The amount of the composition used in or appliedto may vary depending on the nature of the substrate (i.e., fiber orfilm) and the intended application. In most embodiments, the odorcontrol composition constitutes from about 2.5 to about 50 wt. % of thesubstrate, in some embodiments from about 5 to about 30 wt. % of thesubstrate, and in some embodiments, from about 10 to about 20 wt. % ofthe substrate. The adsorbent composition may be applied to a substrateusing any of a variety of well-known application techniques. Forinstance, the composition may be incorporated within the matrix of thesubstrate and/or applied to the surface thereof. Suitable techniques forapplying an aqueous composition to a substrate include spraying,dipping, aqueous coating, printing, and so forth. Techniques forapplying non-aqueous compositions include various melt extrusiontechniques previously described.

The compositions can be incorporated into a variety of articlesincluding film, non-wovens, sachets, inserts, filters, couplings, vents,caps, closures, trays, lids, laminated foils, sheets, etc.

A food package article or food package component of the disclosure canbe, for example, a package component such as a tray, a packing liner, abarrier layer, a scavenger layer, and like components, or combinationsthereof. Long-established food packaging concepts are limited in theirability to extend the shelf-life of food products. Innovative foodpackaging concepts of the disclosure can, for example, interact with theenvironment inside the package and respond by changing their propertiesto maintain, adjust or improve the specific package headspace atmosphereor minimize food flavor loss to the package by “scalping” (i.e., uptakeof volatile components by the polymeric package material from the food)thereby adding to product quality and extending shelf-life. The mostnotable group of technologies in use today for controlling packageheadspace oxygen is oxygen scavengers.

The present disclosure relates to the use of the packaged food contactpolymer layer to selectively remove undesirable off-flavors from thepackaged foods. A food package contact layer can be constructed toremove offensive odors/aromas from the interior of food packagesproduced by, for example, lipid oxidation, lipid hydrolysis,protein/amino acid breakdown, and like changes or reactions of thepackaged food. These active packaging polymer improvements of thedisclosure are significant compared to conventional polyolefins and canconsiderably improve food taste over the shelf-life term of the product.

A film or a multilayer film can be used as a food packaging film,wherein at least one layer has a composition that can adsorb off odorsor plant hormones such as ethylene in static condition and obtainsurprising adsorption in dynamic conditions. Principal manufacturingprocesses used in producing packaging materials include, for example,cast film extrusion, blown-film extrusion (tubular), extrusion coating,extrusion lamination, adhesive laminations, oriented extruded films,blow molding, injection molding, and compression molding. For packagingpurposes, thermoplastics can usually be processed into one of thefollowing structural categories: flexible films, rigid sheets, bottlesand tubs. The film can contain a source of ferric Fe(III) iron and apolyethylenimine (PEI) or a coating thereof. The adsorbent compositioncan comprise a coating comprising a Fe(III) compound and a PEI compoundin at least a monolayer coating. In yet another embodiment of theinvention, CD grafted polymers of the invention can be provided as aFe(III) or PEI coated web of film or as nonwoven fibers, wherein a pieceof web is simply added to a package that is then filled with freshfruits, vegetables, or flowers. In such an embodiment, the packagingmaterial used can be any suitable material and is not limited in anyway. Commonly used packaging materials such as polyethylene, PLA orpolyester, and the like can be used without any limitation, as thecomposition of the invention is simply added to the finished packagingalong with the fresh produce to be packaged. Since the composition ispresent in a separate material, it can be added to any package whereundesirable vapor phase substances are desirably scavenged.

The compositions may be formed into a face mask. A face mask can use thematerials to reduce halitosis. The adsorbent uses at a minimum acombination of a polyethyleneimine (PEI) and an Fe(III) compoundsufficient to achieve at least 20% reduction in H₂S. The combination ofthe polymeric amine compound and the iron compound provides enhancedremoval of malodorous compounds such as hydrogen sulfide, alkyl sulfide,small molecule C₃₊ acids or alcohols, diethylamine and other compoundsknown to cause offensive or malodorous breath and achieves surprisingdynamic activity.

Disposable face masks have been manufactured for many years. Face masksinclude a plurality of layers of selected fibrous materials. Thisinvention relates to disposable face mask materials having a relativelylow pressure drop to permit easy breathing, while preventing odorousvapors from passing through the mask structure. The inventive face maskmaterials comprise different types of fibrous non-woven (e.g., spunbond,meltblown and spunbond/meltblown) or cellulosic filter material having arange of basis weights. The selection of these materials provide for thedesired degree of filtering or barrier to germs while at the same timehaving the desired properties to mitigate unpleasant odor in air passingthrough the mask to the wearer or through the mask from the exhaledbreath of the mask wearer. Materials used in a face masks are meant tohelp block large-particle droplets, splashes, sprays or splatter thatmay contain germs (viruses and bacteria) from reaching the wearer'smouth and nose. Face masks may also help reduce exposure of the wearer'ssaliva and respiratory secretions to others. The mask has significanttechnical advantages in that the face mask materials provide for germbarrier properties and, in addition, prevents the passage of odorousvapors (e.g., hydrogen sulfide—H₂S, methanethiol—CH₃SH,dimethylsulfide—CH₃SCH₃). Desirable barrier materials are engineered tofreely pass air in either direction, while restricting the passage ofodorous vapor components. It will be appreciated that more than onenon-woven or cellulosic barrier material may be used to accomplishspecific performance requirements.

Breathed air treatment is achieved by air flow through most of the areaof the face mask. One or more layers of fibrous filter material in themask are surface treated with a composition to remove noxious vaporsincluding non-condensable gasses from the air passing either directionthrough the mask. Surface treatment compositions do not change themodulus in nonwoven face mask materials. Typical disposable face maskscomprise three layers—an outer layer, an inside layer and interior masklayer. Any layer or combinations can be coated. The outermost face masklayer serves as a partial barrier to droplets, splashes, sprays orsplatter. Face masks are held to minimum requirements in BacterialFiltration Differential, Pressure Efficiency (BFE), Sodium ChlorideAerosol Challenge—NIOSH, Viral Filtration Efficiency (VFE) and SyntheticBlood Penetration-Splash Resistance.

The Bacterial Filtration Efficiency (BFE) test is performed onfiltration materials and devices such as face masks, surgical gowns,caps, and air filters, which are designed to provide protection againstbiological aerosols. The test determines the filtration efficiency ofthese materials when challenged with a biological aerosol ofStaphylococcus aureus. The BFE test procedure is based on MilitarySpecification 36954C and can evaluate filtration efficiencies up to99.9%. This test is required by the ASTM F2100 and EN 14683, as well asused for 510K submissions to the FDA. The test is performed incompliance with Military Specification 36954C, ASTM F2101, and ASTMF2100.

The Differential Pressure test determines the air exchange differentialof porous materials such as surgical face masks and other filtrationdevices. This test was designed after the Military Specification 36954Cand is commonly requested for samples submitted for Bacterial FiltrationEfficiency (BFE) testing. The test is required by ASTM F2100, EN 14863,and is used for 510K submissions to the FDA.

The Sodium Chloride Aerosol Challenge (NaCl)—NIOSH RespiratorPre-qualification test uses a widely accepted method for evaluatingparticle penetration and air flow resistance properties of a variety offiltration materials. This test is able to determine filtrationefficiency measurements up to 99.999%. Respirators must be pre-qualifiedbefore submitting to NIOSH for certification; other materials, such asbreathing system filters and face masks, are tested to determinefiltration efficiency for marketing. Testing is performed in compliancewith 42 CFR Part 84 and NIOSH Procedure No. RC-APR-STP-0057, 0058, and0059.

The Viral Filtration Efficiency test determines the filtrationeffectiveness of various filtration materials such as masks and filtermaterial. This test is necessary for making marketing claims as to theviral filtration efficiency of the mask or other filter material. Thistest has been adapted from the ASTM F2101

The Synthetic Blood Penetration—Splash Resistant test is one of twodifferent synthetic blood resistance tests offered by Nelson Labs todetermine a product's ability to act as a barrier to blood-bornepathogens. The Splash Resistant test method challenges medical facemasks with a fixed volume of synthetic blood directed at high velocityat the center of the mask. This test is required by ASTM F2100 and istested in compliance with ASTM Method F1862, ASTM F2100, and EN14683.

The mask has an outer layer, an interior comfort layer adjacent to theskin and one or more inside adsorbent layers placed there between. Theselayers are made of spunbond. meltblown or cellulosic materials typicalin this manufacture. Such materials include a spunbond with a basisweight about 20 to 30 g·m⁻²; a meltblown with a basis weigh of about 17to 26 g·m⁻²; a combined meltblown/spunbond with a basis weight of about30 to 40 g·m⁻²; a cellulose comfort layer can be used with a basisweight of about 17 to 21 g·m⁻².

The outer mask layer can be constructed from nonwovens such as spun bondpolypropylene, a cellulosic tissue or spun bond polyester. Spun bondfiber may also be made of bicomponent fiber with, for example,polyethylene. The outer layer typically has preferably a basis weightrange of 15 to 35 g·m⁻² (0.45 oz·yd⁻² to 1.0 oz·yd⁻²).

Interior comfort mask layer is preferably composed of nonwovens. Theselayers may also be constructed from polyester and/orpolyolefin(polyethylene or polypropylene) material or cellulosic tissue.Inner layers typically have a basis weight range of 13 to 30 g·m⁻² (0.4oz·yd⁻² to 0.85 oz·yd⁻²), preferably about 13-25 g·m⁻² in basis weights.The interior layers can be effectively coated.

The inside adsorbent mask layer can be a meltblown polyolefin woven ornon-woven with a basis weight of 15 to 30 g·m⁻² and an adsorbentcoating. One embodiment is typically constructed from a meltblownpolypropylene, but may be constructed from meltblown polyolefin,polyester or urethane. The layer(s) may include one two or multiplecoated or uncoated interior layers. The interior layer material has goodgas permeability characteristics and permits air to pass through thefilter body in both directions. The interior layer is a nonwoven withthe adsorbent compositions preferably in a fiber coating. Covering thenose and mouth with the face mask results in warm, moist air exhaled bythe wearer. The exhaled air has a tendency to result in the highconcentration of moisture vapor contained within the mask. Removal ofodorous vapors is not affected as moisture accumulates on the surface ofthe fiber during use.

We have shown a substantial improvement in adsorption as tested by adynamic hydrogen sulfide (H₂S). Dynamic H₂S test method involvesanalytical techniques designed to measure the odor attenuationperformance of a nonwoven face mask structure using a dynamicolfactometer presentation gradient of H₂S. The test olfactometersimulates a dynamic hydrogen sulfide concentration based on the distanceof 12 inches (30.5 cm) from source using a flow rate of 7 liters perminute. For example, a hydrogen sulfide concentration of 200 ppbmeasured in the oral cavity will have a concentration of 20 ppb at thetypical distance of 12 inches at a 10 liter/minute breathing rate. Oralcavity hydrogen sulfide can range from less than 20 ppb (vol/vol) tomore than 1,000 ppb (vol/vol). Sulfur gases such as hydrogen sulfide andmethylmercaptan (methanethiol) (CH₃SH) together are often implicated forhalitosis malodors. “Socially accepted” oral cavity hydrogen sulfide isless than 250 ppb (vol/vol). The method measures the attenuation of H₂Sacross the face mask structure. This procedure allows for thedetermination of the following compound:

Malodor and Concentration Test Compound ppb (nl/L) Hydrogen sulfide(H₂S) 5 to 500

In this test method, three steps are involved. They are (a) theinstrument sensitivity calibration, (b) dynamic face mask testing tomeasure H₂S attenuation, and (c) the quality control of the test.

Face mask structure is tested in a 13 cm diameter glass permeation cell(FIG. 1) mounted on an olfactometer. FIG. 1 shows a glass test a devicefor testing mask structure under dynamic flow of hydrogen sulfide. InFIG. 1 the glass test device 10 includes a first enclosure 12 a and asecond enclosure 12 b. The volume is defined by enclosures 12 AM 12 be aseparated by the test nonwoven 11 positioned there between. The inflow13 is provided continuously at a defined rate by an olfactometer device(not shown). The outflow 14 is measured for hydrogen sulfide using anappropriate measuring device. Aluminum clamp rings, fitted on eitherside of the glass flask flanges, are tightened using six screws tohermetically sealing the face mask structure between the two flasksglass flanges. Dynamic flow from the olfactometer (St. Croix SensoryAC'SCENT® Olfactometer) is delivered into the inflow end of thepermeation cell at 7 liters per minute for a 15 consecutive minute testperiod for a total flow volume of 105 liters. A Jerome 631-X hydrogensulfide test meter is used to measure the H₂S concentration as afunction of time; inflow and outflow H₂S concentrations are measured.Before starting the test, nonwoven webs mounted in the permeation cellare humidified by breathing across the fibers with seven lung volumes ofair. The permeation cell is then mounted over the olfactometer flowport. Three hydrogen sulfide measurements are taken at 1, 5 and 15minutes in duplicate. The values are average over the 15 minute testperiod and reported in ppb (vol/vol).

Hydrogen sulfide is a common test malodor and can be used to predict theactivity of other sulfur compound malodors. The attenuation rate(percent reduction) of H₂S is calculated from average H₂S concentrationsof control and coated samples. An H₂S reduction greater than 20% isacceptable as an indication that malodor control can be achieved. Theperformance of the coated nonwoven fiber face mask structure isdetermined from the H₂S vapor mass taken up by the coated fiber comparedto the control mask structure over the fifteen minute test time (controlfiber structure−coated fiber structure)÷control fiber structure×100=%H₂S Reduction.

The hydrogen sulfide sorptions of compositions illustrated below areapplied to a fiber substrate to mitigate unwanted or target substancespassing through fibrous layers of a face mask. The amount of thecomposition used or applied to the fiber surface may vary depending onthe non-woven (e.g., spunbond, meltblown and spunbond/meltblown) orcellulosic filter material as well as the material basis weight and theintended application. In most embodiments, the odor control compositionconstitutes from about 1.5 to about 30 wt. % of the substrate, in someembodiments from about 3 to about 20 wt. % of the substrate, and in someembodiments, from about 5 to about 10 wt. % of the substrate. Thecomposition may be applied to a substrate using any of a variety ofwell-known application techniques. For instance, the aqueouscompositions can be applied to the surface using suitable techniquesincluding spraying, dipping, aqueous coating, etc. The compositions canbe made with amounts of the components as shown in the following table.

Fiber Coating Compositions First Second Third Embodiment EmbodimentEmbodiment (Wt % on (Wt % on (Wt % on Components polymer) polymer)polymer) Fiber substrate 98 90 70 Polyethylenimine 1.5 6 10 FerricHydroxide 0.5 4 20 Optimum Coating Formula Materials Wt.-% on solutionWt.-% on solids PEI EPO MIN 0.65 19 FeCl₃ 1.25 37 KOH 1.5 44 DeionizedWater (pH 12.5) 96.6 — Totals 100 100

In the examples section below, material compositions and detailed samplepreparation information for each coated fibrous material is provided.

EXAMPLE 1

Aqueous coating solutions are prepared in 100 gram and 50 grams batchesfor hand coating fiber substrates. With coating formulations A and B,the order of addition is water and potassium ferrate. The solution ismechanically stirred until a reddish ferric hydroxide floc forms, thenethanol and glycerin are added. Lastly, Polyethylenimine (Aldrich181978) is added as a 10 wt.-% solution (water accounted for in overallformulation).

Meltblown (MB) nonwoven polypropylene fiber and cellulosic paper samples(stored in a 20° C./50% RH room) are cut into 16.5 cm×16.5 cm handsheets and accurately weighed to 0.1 milligrams. MB fiber control is 27g/m² polypropylene; the coated MB fiber contained 2 wt % alpha CDgrafted onto maleic anhydride grafted polypropylene.

Two basis weight cellulosic papers (15 g/m² and 65 g/m²) are tested.

An accurate volume of solution is transferred to the sheet using a Mohrpipette. Since the coating solution is hydrophilic relative thehydrophobic polypropylene fiber, the coating solution is dispersed intothe fiber sheet uniformly using a rubber ink roller.

Cellulosic paper sheets are starch sized requiring a rubber ink rollerto uniformly disperse the coating solution into the fiber. The sheet isturned over and the coating process is repeated.

Coated sample sheets are place on a porous drying screen and allowed toair dry overnight in a 20° C./50% RH room. Coated sheets are re-weighedand coating weight calculated (coated sheet wt.−uncoated sheetwt.)/uncoated sheet wt.×100%=coating wt %. Coating formulation C isprepared from a borate/phosphate buffer. A 0.001 molar sodium boratesolution (1 mM NaOH, pH ˜8.2) is prepared by adding 0.040 g NaOH (50%Solution), to 500 ml distilled water, then 0.118 g boric acid. Finalsolution is filtered by 0.2 micron filter membrane. The 0.005 molarphosphate/0.001 molar borate buffer (pH ˜9) is prepared by adding 0.670g Na₂HPO₄.7H₂O to 500 mL borate solution. The potassium ferrate,ethanol, glycerin and polyethylenimine are added as previouslydescribed. Coated sheets are prepared and coating weights determined asexpressed above.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) MB nonwoven and cellulosic papersheets and identical sample sheets coated with coating formulations A, Band C. A plurality of layers of selected fibrous materials—MBpolypropylene and cellulosic paper—is tested using the previouslydescribed hydrogen sulfide sorption method. Control sheets were found tosorb no hydrogen sulfide by comparing upstream hydrogen sulfidemeasurements before the sample test sheets and down stream hydrogensulfide measurements after passing through the sample test sheets.

A B C Material Wt.-% Wt.-% Wt.-% Polyethylenimine 0.50 0.50 0.50 Ethanol5.0 5.0 5.0 Glycerin 0.50 0.50 0.25 Potassium Ferrate 0.04 0.09 0.040.001M borate/0.005M 94.2 phosphate buffer D.I. Water 94.0 94.0 Total100.0 100.0 100 pH 12.0 12.0 8.0

Number Surface Ave. Layers Basis Coating Coating H₂S Conc. % H₂SMeltblown Wt. g/m² ID Wt.-% ppb (vol/vol) Reduction 2 27 Ctrl — 23.4 — 127 A 2.5 19.8 16 2 27 Ctrl — 21.0 — 3 27 B 2.7 19.8 6 1 27 B 2.7 16.0 241 27 B 2.7 16.8 20 2 27 Ctrl — 22.8 — 2 27 C 2.5 21.4 6 2 27 C 2.5 20.211 2 27 Ctrl — 25.3 — 2 27 B 30   15.8 38

Number Number Surface Ave. Layers Basis Layers Basis Coating Coating H2SConc. % H₂S Cellulose Wt. g/m² Cellulose Wt. g/m² ID Wt.-% ppb (vol/vol)Reduct'n 3 15 — — — — 24.5 — 3 15 — — B 27 19.5 20 1 65 1 27 — — 32 — 165 1 27 B 15/30 18.3 43

EXAMPLE 2

The aqueous coating solution is prepared in 100 gram and 50 gramsbatches for hand coating fiber substrates. The order of addition iswater and potassium ferrate. The solution is stirred until a reddishferric hydroxide floc forms, then ethanol is added. Lastly,Polyethylenimine (Aldrich 181978) is added as a 10 wt.-% solution (wateraccounted for in overall formulation). A plurality of layers of nonwovenmaterials—meltblown (MB) and spunbond (SB) polypropylene—(stored in a20° C./50% RH room) are cut into 16.5 cm×16.5 cm hand sheets andaccurately weighed to 0.1 milligrams. Polypropylene MB and SB fibercontrols are 21 g/m² and 27 g/m² webs, respectively; the coated spunbondfiber samples contained 2 wt % alpha CD grafted to maleic anhydridegrafted polypropylene while the meltblown doesn't contain CD. Cellulosicpaper webs are 19 g/m². An accurate volume of solution is transferred tothe sheet using a Mohr pipette. Since the coating solution ishydrophilic relative the hydrophobic polypropylene fiber, the coatingsolution is dispersed into the fiber sheet uniformly using a rubber inkroller. Cellulosic paper sheets are starch sized requiring a rubber inkroller to uniformly disperse the coating solution into the fiber. Thesheet is turned over and the coating process is repeated. Coated samplesheets are place on a porous drying screen and allowed to air dryovernight in a 20° C./50% RH room. Coated sheets are re-weighed andcoating weight calculated. Coating formulation C is prepared from aborate/phosphate buffer.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) MB nonwoven and cellulosic papersheets and identical sample sheets coated with coating formulation. Aplurality of layers of selected fibrous materials—MB, SB and cellulosicpaper—is tested. Control sheets were found to sorb no hydrogen sulfideby comparing upstream hydrogen sulfide measurements before the sampletest sheets and down stream hydrogen sulfide measurements after passingthrough the sample test sheets.

Material Wt.-% Polyethylenimine 1.0 Ethanol 10.0 Potassium Ferrate 0.35D.I. Water 88.65 Total 100.0 pH 12.2

Number Number Number Surface Ave. Layers Basis Layers Basis Layers BasisCoating Coating H₂S Conc. % H₂S MB Wt. g/m² SB Wt. g/m² Cellulose Wt.g/m² ID Wt.-% ppb (vol/vol) Reduction 1 21 1 27 1 19 Ctrl — 29.5 — 1 211 27 1 19 Ex 2 22/12/6 21.1 28 1 21 2 27 Ex 2 10/11.5 18.6 37

EXAMPLE 3

Aqueous coating solutions are prepared in 100 gram and 50 grams batchesfor hand coating fiber substrates. With coating formulations D, E and F,the order of addition is water and potassium ferrate. The solution ismechanically stirred until a reddish ferric hydroxide floc forms.Lastly, Polyethylenimine (Aldrich 181978) is added as a 10% solution(water accounted for in overall formulation). A plurality of layers ofnonwoven materials—spunbond/meltblown (S/M) and spunbond (SB)—(stored ina 20° C./50% RH room) are cut into 16.5 cm×16.5 cm hand sheets andaccurately weighed to 0.1 milligrams. The polypropylene S/M and SB fibercontrol are 30 g/m² and 27 g/m², respectively. The coated SB fibersamples contained 2 wt % alpha CD grafted onto maleic anhydride graftedpolypropylene. Coated S/M fiber is not CD modified. An accurate volumeof solution is transferred to the sheet using a Mohr pipette. Since thecoating solution is hydrophilic relative the hydrophobic polypropylenefiber, the coating solution is dispersed into the fiber sheet uniformlyusing a rubber ink roller. The sheet is turned over and the coatingprocess is repeated. Coated sample sheets are place on a porous dryingscreen and allowed to air dry overnight in a 20° C./50% RH room. Samplesheets are weighed and coating weights calculated.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) meltblown nonwoven and cellulosicpaper sheets and sample sheets coated with coating formulations D, E andF. A plurality of layers of selected fibrous materials—S/M, MB andcellulosic paper—is tested. Control sheets were found to sorb nohydrogen sulfide by comparing upstream hydrogen sulfide measurementsbefore the sample test sheets and downstream hydrogen sulfidemeasurements after passing through the sample test sheets. At the end ofthe 15 minute sorption test, coated nonwoven fibers mounted in thepermeation cell are re-humidified by breathing across the fibers withseven lung volumes of air. The permeation cell is then re-mounted overthe olfactometer flow port. Two hydrogen sulfide measurements are takenat 17 minutes. The re-humidified 17 minute average values are about 4ppb (vol/vol) lower then the 15 minute reading. Re-humidified uncoatedcontrol nonwoven fiber showed about one ppb (vol/vol) lower the 15minute reading.

D E F Material Wt.-% Wt.-% Wt.-% Polyethylenimine 1.2 0.65 0.30Potassium Ferrate 1.0 1.0 1.0 D.I. Water 97.8 98.3 98.7 Total 100.0 100100.0 pH 12.5 12.2 12.0

Number Number Surface Ave. Layers Basis Layers Basis Coating Coating H₂SConc. % H₂S S/M Wt. g/m² SB Wt. g/m² ID Wt.-% ppb (vol/vol) Reduct'n 227 Ctrl — 27.4 — 2 27 D 24 19.8 28 2 27 E 12 18.6 32 2 27 F 13 20.0 27 230 E 13 17.3 37 2 30 1 27 Ctrl — 30.1 — 2 30 1 27 E 17/21 37 37 2 30 127 E 17/21 41 41 2 27 Ctrl — 29 — 2 27 E 13 19.6 32 2 27 E 13 20.9 28 227 E  3 17.1 41

EXAMPLE 4

The aqueous coating solution is prepared in 100 gram and 50 gramsbatches for hand coating fiber substrates. The order of addition iswater and potassium ferrate. The solution is mechanically stirred untila reddish ferric hydroxide floc forms. Then polyethylenimine (Aldrich181978) is added as a 10 wt.-% solution (water accounted for in overallformulation). Meltblown (MB) nonwoven polypropylene fiber and cellulosicpaper samples (stored in a 20° C./50% RH room) are cut into 16.5 cm×16.5cm hand sheets and accurately weighed to 0.1 milligrams. MB fibercontrol is 27 g/m² polypropylene; the coated MB fiber contained 2 wt %alpha CD grafted onto maleic anhydride grafted polypropylene. Thecellulosic paper—control and coated samples—is 55 g/m². An accuratevolume of solution is transferred to the sheet using a Mohr pipette.Since the coating solution is hydrophilic relative the hydrophobicpolypropylene fiber, the coating solution is dispersed into the fibersheet uniformly using a rubber ink roller. The sheet is turned over andthe coating process is repeated. Cellulosic paper sheets are starchsized requiring a rubber ink roller to uniformly disperse the coatingsolution into the fiber. Coated sample sheets are place on a porousdrying screen and allowed to air dry overnight in a 20° C./50% RH room.Sample sheets are weighed and coating weights calculated.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) MB nonwoven and cellulosic papersheets and sample sheets coated with coating formulation. A plurality oflayers of selected fibrous materials—MB polypropylene and cellulosicpaper—is tested. Control sheets were found to sorb no hydrogen sulfideby comparing upstream hydrogen sulfide measurements before the sampletest sheets and down stream hydrogen sulfide measurements after passingthrough the sample test sheets.

Material Wt.-% Polyethylenimine 0.77 Potassium Ferrate 3.80 D.I. Water95.43 Total 100.0 pH 12.2

Number Surface Ave. Layers Basis Coating Coating H₂S Conc. % H₂SMeltblown Wt. g/m² ID Wt.-% ppb (vol/vol) Reduct'n 2 27 — — 32.9 — 2 27Ex 4 19 29.8 10 2 27 Ex 4 17 29.0 12

Number Surface Ave. Layers Basis Coating Coating H₂S Conc. % H₂SCellulose Wt. g/m² ID Wt.-% ppb (vol/vol) Reduct'n 1 55 — — 23.1 — 1 55Ex 4 2 15.6 32

EXAMPLE 5

Aqueous coating solutions are prepared in 100 gram and 50 grams batchesfor hand coating fiber substrates. With coating formulations G and H,the order of addition is water and ferric chloride. The solution ismechanically stirred to dissolve the ferric chloride. Next, the ferricchloride solution is neutralized with 10 wt.-% potassium hydroxide(water accounted for in overall formulation) producing a ferrichydroxide floc. Then polyethylenimine (Aldrich 181978 or EPOMIN P1000)is added as a 10 wt.-% solution (water accounted for in overallformulation). Final coating solution pH is adjusted with 10% potassiumhydroxide to pH 12.5. Spunbond (SB) nonwoven polypropylene fiber samples(stored in a 20° C./50% RH room) are cut into 16.5 cm×16.5 cm handsheets and accurately weighed to 0.1 milligrams. SB fiber control is 27g/m² polypropylene; the coated SB fiber contained 2 wt % alpha CDgrafted onto maleic anhydride grafted polypropylene. An accurate volumeof solution is transferred to the sheet using a Mohr pipette. Since thecoating solution is hydrophilic relative the hydrophobic polypropylenefiber, the coating solution is dispersed into the fiber sheet uniformlyusing a rubber ink roller. The sheet is turned over and the coatingprocess is repeated. Coated sample sheets are place on a porous dryingscreen and allowed to air dry overnight in a 20° C./50% RH room. Samplesheets are weighed and coating weights calculated.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) spunbond non-woven and 2 wt % alphaCD grafted onto maleic anhydride grafted polypropylene SB sample sheetscoated with coating formulation. A plurality of layers of SB fiber istested. Control sheets were found to sorb no hydrogen sulfide bycomparing upstream hydrogen sulfide measurements before the sample testsheets and down stream hydrogen sulfide measurements after passingthrough the sample test sheets. At the end of the 15 minute sorptiontest, coated SB fibers mounted in the permeation cell are re-humidifiedby breathing across the fibers with seven lung volumes of air. Thepermeation cell is then re-mounted over the olfactometer flow port. Twohydrogen sulfide measurements are taken at 17 minutes. The re-humidified17 minute average values are about 3 ppb (vol/vol) lower the 15 minutereading. Re-humidified uncoated control nonwoven fiber showed about oneppb (vol/vol) lower the 15 minute reading.

G H Material Wt.-% Wt.-% Polyethylenimine 0.65 (Aldrich 181978)Polyethylenimine 0.65 (EPOMIN P1000) Ferric Chloride 1.35 1.25 Potassiumhydroxide 1.12 1.12 D.I. Water 96.88 96.98 Total 100.0 100.0 pH 12.512.5

Number Surface Ave. Layers Basis Coating Coating H₂S Conc. % H₂SSpunbond Wt. g/m² ID Wt.-% ppb (vol/vol) Reduction 2 27 — — 22.1 — 2 27G 13 19.3 13 2 27 G 7 18.4 17 2 27 H 7 18.8 15 2 27 H 1.6 21 5

EXAMPLE 6

The aqueous coating solution is prepared in 100 gram and 50 gramsbatches for hand coating fiber substrates. The order of addition iswater and potassium ferrate. The solution is mechanically stirred untila reddish ferric hydroxide floc forms. Then polyethylenimine (Aldrich181978) is added as a 10 wt.-% solution (water accounted for in overallformulation). Lastly, fumed silica is mechanically dispersed into thesolution. Meltblown (MB) nonwoven polypropylene fiber samples (stored ina 20° C./50% RH room) are cut into 16.5 cm×16.5 cm hand sheets andaccurately weighed to 0.1 milligrams. MB fiber control is 27 g/m²polypropylene; the coated MB fiber contained 2 wt % alpha CD graftedonto maleic anhydride grafted polypropylene. An accurate volume ofsolution is transferred to the sheet using a Mohr pipette. Since thecoating solution is hydrophilic relative the hydrophobic polypropylenefiber, the coating solution is dispersed into the fiber sheet uniformlyusing a rubber ink roller. The sheet is turned over and the coatingprocess is repeated. Coated sample sheets are place on a porous dryingscreen and allowed to air dry overnight in a 20° C./50% RH room. Samplesheets are weighed and coating weights calculated.

Hydrogen sulfide sorption is determined by the dynamic hydrogen sulfidetest method for control (uncoated) MB nonwoven and 2 wt % alpha CDgrafted onto maleic anhydride grafted polypropylene MB sample sheetscoated with the coating formulation. A plurality of layers of MBpolypropylene fiber is tested. Control sheets were found to sorb nohydrogen sulfide by comparing upstream hydrogen sulfide measurementsbefore the sample test sheets and down stream hydrogen sulfidemeasurements after passing through the sample test sheets.

Material Wt.-% Polyethylenimine 0.65 Potassium Ferrate 0.70 Fumed silica0.50 D.I. Water 98.15 Total 100.0 pH 12.0

Number Surface Ave. Layers Basis Coating Coating H₂S Conc. % H₂SMeltblown Wt. g/m² ID Wt.-% ppb (vol/vol) Reduction 2 27 — — 22.1 — 2 27Ex 6 7 18.8 15 2 27 Ex 6 1.6 21 5

The foregoing discloses embodiments of the invention. In theSpecification and claims, “about” modifying, for example, the quantityof an ingredient in a composition, concentration, volume, processtemperature, process time, yield, flow rate, pressure, and like values,and ranges thereof, employed in describing the embodiments of thedisclosure, refers to variation in the numerical quantity that canoccur, for example, through typical measuring and handling proceduresused for making compounds, compositions, concentrates or useformulations; through inadvertent error in these procedures; throughdifferences in the manufacture, source, or purity of starting materialsor ingredients used to carry out the methods, and like proximateconsiderations. The term “about” also encompasses amounts that differdue to aging of a formulation with a particular initial concentration ormixture, and amounts that differ due to mixing or processing aformulation with a particular initial concentration or mixture. Wheremodified by the term “about” the claims appended hereto includeequivalents to these quantities. “Optional” or “optionally” means thatthe subsequently described event or circumstance may but need not occur,and that the description includes instances where the event orcircumstance occurs and instances in which it does not. For example, “Aoptionally B” means that B may but need not be present, and thedescription includes situations where A includes B and situations whereA does not include B. “Includes” or “including” or like terms means“includes but not limited to.” The present invention may suitablycomprise, consist of, or consist essentially of, any of the disclosed orrecited elements. Thus, the invention illustratively disclosed hereincan be suitably practiced in the absence of any element which is notspecifically disclosed herein. The use of the singular typicallyincludes and at least does not exclude the plural.

The specification, figures, examples and data provide a detailedexplanation of the invention as it has been developed to date. Theinvention, however, can take the form of nonwovens, fibers, films,sheets, bottles, caps, and other embodiments without departing from thespirit or the intended scope of the invention. The invention thereforeresides in the appended claims.

1. An adsorbent for adsorbing unwanted or target substances from a gasor vapor phase at a concentration of less than 15 part per million, theadsorbent comprising a nonwoven fabric having a coating, the coatingcomprising: a. an Fe compound selected from an alkali metal ferrate, aferric hydroxide or a reaction product of an hydroxide reactant and asource of an Fe(III) compound; and b. a polyethylenimine.
 2. Theadsorbent of claim 1 wherein the source of Fe(III) compound is a ferricsulfate, FeCl₃, Fe(NO₃)₃ or mixtures thereof. 3-4. (canceled)
 5. Theadsorbent of claim 1, wherein the polyethylenimine has a molecularweight (M_(n)) of 800 to 1,000,000 and the adsorbent is substantiallyfree of solid support such as silica.
 6. The adsorbent of claim 1,wherein the polyethylenimine is free of substituents.
 7. The adsorbentof claim 1, wherein the polyethylenimine comprises an ethoxylatedpolyethylenimine.
 8. (canceled)
 9. The adsorbent of claim 1, whereinthere is about 1 to 85 wt % of the Fe(III) compound and 0.1 to 80 wt %of polyethylenimine based on solids content.
 10. The adsorbent articleof claim 1, the adsorbent article comprising a nonwoven substrate havingsurface area.
 11. The article of claim 1 wherein the source of Fe(III)compound is a ferric sulfate, FeCl₃, Fe(NO₃)₃ or mixtures thereof.12-13. (canceled)
 14. The article of claim 10 wherein the substrate hasa surface area of at least 0.1 m² gm⁻¹.
 15. The article of claim 10,wherein the polyethylenimine has a molecular weight (M_(n)) of 800 to1,000,000 and the article is free of a solid support such as silica.16-18. (canceled)
 19. The article of claim 10, wherein there is about0.1 to 35 wt % of the Fe(III) compound and 0.1 to 35 wt % ofpolyethylenimine based on the article.
 20. The article of claim 10wherein the nonwoven substrate comprises substrate comprising apolyolefin or a polyester. 21-23. (canceled)
 24. The article of claim10, wherein the substrate comprises a web having a thickness of about0.01 to 1 mm.
 25. The article of claim 10, wherein the substratecomprises a polyester non-woven.
 26. The article of claim 10, whereinthe substrate comprises a polyolefin non-woven.
 27. The article of claim10 comprising a container comprising a thermoplastic polymer with anenclosed volume, the volume comprising a vapor phase comprising unwantedor target substance. 28-41. (canceled)
 42. The article of claim 10comprising a face mask comprising a fabric layer comprising a nonwovenfabric. 43-54. (canceled)
 55. A method of adsorbing unwanted or targetsubstances from a dynamic gas or vapor phase with the adsorbent of claim1 comprising a nonwoven, the dynamic gas or vapor phase having aconcentration of unwanted or target substances of less than 15 ppm, themethod comprises: i. positioning the adsorbent such that the dynamic gasvapor phase is in contact with the adsorbent at a contact time of lessthan 1 second; and ii. causing the concentration of the unwanted ortarget substance be reduced in the dynamic gas or vapor phase. 56-63.(canceled)
 64. The method of claim 55, wherein in the coating there isabout 0.01 to 80 wt % of the Fe(III)) compound and 0.01 to 80 wt % ofpolyethylenimine based on the solids content of the coating. 65-68.(canceled)
 69. The method of claim 55, wherein the nonwoven comprises aweb having a thickness of about 0.01 to 10 mm.
 70. The method of claim55, wherein the nonwoven comprises a polyester non-woven.
 71. The methodof claim 56, wherein the nonwoven comprises a polyolefin non-woven.